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Modelling the thresholds of nitrogen/phosphorus concentration and hydraulic retention time for bloom

《环境科学与工程前沿（英文）》 2022年 第16卷 第10期 doi: 10.1007/s11783-022-1564-1

摘要：

● A new model for bloom control in open land scape water was constructed.

关键词： Reclaimed water landscape     Algal bloom     Nitrogen and phosphorus     Hydraulic retention time     Threshold     Control model    

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Effects of nitrate concentration on biological hydrogen production by mixed cultures

Bo WANG, Wei WAN, Jianlong WANG,

《环境科学与工程前沿（英文）》 2009年 第3卷 第4期   页码 380-386 doi: 10.1007/s11783-009-0142-0

摘要： The effects of nitrate on fermentative hydrogen production and soluble metabolites from mixed cultures were investigated by varying nitrate concentrations from 0 to 10g N/L at 35°C with an initial pH of 7.0. The results showed that the substrate degradation rate, hydrogen production potential, hydrogen yield, and average hydrogen production rate initially increased with increasing nitrate concentrations from 0 to 0.1g N/L, while they decreased with increasing nitrate concentrations from 0.1 to 10g N/L. The maximum hydrogen production potential of 305.0mL, maximum hydrogen yield of 313.1mL/g glucose, and maximum average hydrogen production rate of 13.3mL/h were obtained at a nitrate concentration of 0.1g N/L. The soluble metabolites produced by the mixed cultures contained only ethanol and acetic acid (HAc) without propionic acid (HPr) and butyric acid (HBu). This study used the Modified Logistic model to describe the progress of cumulative hydrogen production in batch tests. A concise model was proposed to describe the effects of nitrate concentration on average hydrogen production rate.

关键词： nitrogen source     biohydrogen     fermentative hydrogen production     quantitative kinetic model    

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Nitrogen pollution and source identification of urban ecosystem surface water in Beijing

Yufen REN, Zhiwei XU, Xinyu ZHANG, Xiaoke WANG, Xiaomin SUN, D. J. BALLANTINE, Shengzhong WANG

《环境科学与工程前沿（英文）》 2014年 第8卷 第1期   页码 106-116 doi: 10.1007/s11783-012-0474-z

摘要： Nitrogen contamination of surface water is a worldwide environmental problem with intensive agriculture and high population densities. We assessed the spatial and seasonal variation in concentrations of total nitrogen and different nitrogen species present in surface-water in Beijing, China. Also, chemical ( ) and isotopic ( ) indicators were used to identify nitrate sources. The results showed that, during 2009 and 2010, nitrate nitrogen concentrations ranged from 0.7 to 7.6 mg·L , ammonium nitrogen from 0.1 to 3.4 mg·L , and total nitrogen from 2.4 to 17.0 mg·L . Inorganic nitrogen accounted for between 60 and 100% of total nitrogen at the ten monitoring sites. Nitrate nitrogen, ammonium nitrogen, and total nitrogen concentrations at the 2 downstream monitoring sites in south-eastern Beijing were significantly higher than those at the other eight upstream monitoring sites ( <0.01). Examination of seasonal variation showed that there was a significant inverse relationship between nitrate nitrogen concentrations and precipitation, and that nitrate nitrogen concentrations peaked in the dry seasons. The information given by the values and nitrate nitrogen concentrations, combined with the ratio distribution, showed that domestic sewage was the major source of nitrate in Beijing. Methods to control and reduce sewage pollution are urgently needed to help manage surface water quality in Beijing.

关键词： nitrogen concentration     spatial and seasonal variation     stable nitrogen isotope     urban ecosystem     source    

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Mechanism studies on nitrogen removal when treating ammonium-rich leachate by sequencing batch biofilm

XU Zhengyong, YANG Zhaohui, ZENG Guangming, XIAO Yong, DENG Jiuhua

《环境科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 43-48 doi: 10.1007/s11783-007-0008-2

摘要： The nitrogen removal mechanism was studied and analyzed when treating the ammonium-rich landfill leachate by a set of sequencing batch biofilm reactors (SBBRs), which was designed independently. At the liquid temperature of (32?0.4)?C, and after a 58-days domestication period and a 33-days stabilization period, the efficiency of ammonium removal in the SBBR went up to 95%. Highly frequent intermittent aeration suppressed the activity of nitratebacteria, and also eliminated the influence on the activity of anaerobic ammonium oxidation (ANAMMOX) bacteria and nitritebacteria. This influence was caused by the accumulation of nitrous acid and the undulation of pH. During the aeration stage, the concentration of dissolved oxygen was controlled at 1.2 1.4 mg/L. The nitritebacteria became dominant and nitrite accumulated gradually. During the anoxic stage, along with the concentration debasement of the dissolved oxygen, ANAMMOX bacteria became dominant; then, the nitrite that was accumulated in the aeration stage was wiped off with ammonium simultaneously.

关键词： undulation     33-days stabilization     concentration debasement     temperature     accumulation    

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A Novel Electrochemical Reactor for Nitrogen and Phosphorus Recovery from Domestic Wastewater

Shiting Ren, Mengchen Li, Jianyu Sun, Yanhong Bian, Kuichang Zuo, Xiaoyuan Zhang, Peng Liang, Xia Huang

《环境科学与工程前沿（英文）》 2017年 第11卷 第4期 doi: 10.1007/s11783-017-0983-x

摘要： To separate and concentrate NH4+ and PO43 from the synthetic wastewater to the concentrated solution through a novel electrochemical reactor with circulated anode and cathode using the difference of the concentration between electrode chamber and middle chamber. In recent years, the research on electrochemical processes have been focused on phosphate and ammonium removal and recovery. Among the wide range of possibilities with regards to electrochemical processes, capacitive deionization (CDI) saves the most energy while at the same time does not have continuity and selectivity. In this study, a new electrochemical reactor with electrolyte cyclic flowing in the electrode chambers was constructed to separate and concentrate phosphate and ammonium continuously and selectively from wastewater, based on the principle of CDI. At the concentration ratio of NaCl solution between the electrode chambers and the middle chamber (r) of 25 to 1, phosphate and ammonium in concentration level of domestic wastewater can be removed and recovered continuously and selectively as struvite. Long-term operation also indicated the ability to continuously repeat the reaction and verified sustained stability. Further, the selective recovery at the certain r could also be available to similar technologies for recovering other kinds of substances.

关键词： Nutrients recovery     Electrochemical reactor     Electrolyte cyclic flowing     Concentration ratio     Struvite    

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Localized high-concentration electrolytes for lithium metal batteries: progress and prospect

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1354-1371 doi: 10.1007/s11705-022-2286-4

摘要： With the increasing development of digital devices and electric vehicles, high energy-density rechargeable batteries are strongly required. As one of the most promising anode materials with an ultrahigh specific capacity and extremely low electrode potential, lithium metal is greatly considered an ideal candidate for next-generation battery systems. Nevertheless, limited Coulombic efficiency and potential safety risks severely hinder the practical applications of lithium metal batteries due to the inevitable growth of lithium dendrites and poor interface stability. Tremendous efforts have been explored to address these challenges, mainly focusing on the design of novel electrolytes. Here, we provide an overview of the recent developments of localized high-concentration electrolytes in lithium metal batteries. Firstly, the solvation structures and physicochemical properties of localized high-concentration electrolytes are analyzed. Then, the developments of localized high-concentration electrolytes to suppress the formation of dendritic lithium, broaden the voltage window of electrolytes, enhance safety, and render low-temperature operation for robust lithium metal batteries are discussed. Lastly, the remaining challenges and further possible research directions for localized high-concentration electrolytes are outlined, which can promisingly render the practical applications of lithium metal batteries.

关键词： high-concentration electrolyte     localized high-concentration electrolyte     lithium metal battery     solid electrolyte interphase     dendrite    

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PM concentration declining saves health expenditure in China

《环境科学与工程前沿（英文）》 2023年 第17卷 第7期 doi: 10.1007/s11783-023-1690-4

摘要：

● Monthly hospitalization expenses are sensitive to increases in PM2.5 exposure.

关键词： Air pollution     Health expenditure     PM2.5 concentration     Economic impact     Heterogeneous effect    

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Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 595-608 doi: 10.1007/s11709-021-0720-1

摘要： The effective notch stress approach for evaluating the fatigue strength of rib–deck welds requires notch stress concentration factors obtained from complex finite element analysis. To improve the efficiency of the approach, the notch stress concentration factors for three typical fatigue-cracking modes (i.e., root–toe, root–deck, and toe–deck cracking modes) were thoroughly investigated in this study. First, we developed a model for investigating the effective notch stress in rib–deck welds. Then, we performed a parametric analysis to investigate the effects of multiple geometric parameters of a rib–deck weld on the notch stress concentration factors. On this basis, the multiple linear stepwise regression analysis was performed to obtain the optimal regression functions for predicting the notch stress concentration factors. Finally, we employed the proposed formulas in a case study. The notch stress concentration factors estimated from the developed formulas show agree well with the finite element analysis results. The results of the case study demonstrate the feasibility and reliability of the proposed formulas. It also shows that the fatigue design curve of FAT225 seems to be conservative for evaluating the fatigue strength of rib–deck welds.

关键词： notch stress concentration factor     rib–deck weld     parametric analysis     regression analysis     parametric equation    

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SUSTAINABLE NITROGEN MANAGEMENT IN AUSTRALIAN AGROECOSYSTEMS: CHALLENGES AND OPPORTUNITIES

《农业科学与工程前沿（英文）》 2022年 第9卷 第3期   页码 366-372 doi: 10.15302/J-FASE-2022447

摘要：

● There is huge potential for improvement of nitrogen management in Australia.

关键词： Australian agroecosystems     reactive nitrogen     sustainable development    

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SUSTAINABLE NITROGEN MANAGEMENT FOR VEGETABLE PRODUCTION IN CHINA

《农业科学与工程前沿（英文）》 2022年 第9卷 第3期   页码 373-385 doi: 10.15302/J-FASE-2022455

摘要：

● Sustainable nitrogen management strategies for Chinese vegetable production are summarized.

关键词： enhanced-efficiency nitrogen fertilizer     integrated knowledge and products strategy     nitrogen rate     reactive nitrogen loss     vegetable     yield    

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EFFECTS OF SUBSTITUTION OF MINERAL NITROGEN WITH ORGANIC AMENDMENTS ON NITROGEN LOSS FROM SLOPING CROPLAND

《农业科学与工程前沿（英文）》 2022年 第9卷 第3期   页码 396-406 doi: 10.15302/J-FASE-2022456

摘要：

● Interflow acts as the dominant pathway for N loss loadings.

关键词： improved fertilization regime     interflow     nitrogen forms     nitrogen leaching     purple soil     sloping cropland    

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Nitrogen distribution in the products from the hydrothermal liquefaction of sp. and sp.

《化学科学与工程前沿（英文）》 2022年 第16卷 第6期   页码 985-995 doi: 10.1007/s11705-021-2126-y

摘要： The high contents of nitrogen-containing organic compounds in biocrude obtained from hydrothermal liquefaction of microalgae are one of the most concerned issues on the applications and environment. In the project, Chlorella sp. and Spirulina sp. were selected as raw materials to investigate the influence of different reaction conditions (i.e., reaction temperature, residence time, solid loading rate) on the distribution of nitrogen in the oil phase and aqueous phase. Three main forms of nitrogen-containing organic compounds including nitrogen-heterocyclic compounds, amide, and amine were detected in biocrudes. The contents of nitrogen-heterocyclic compounds decreased with temperature while amide kept increasing. The effect of residence time on the components of nitrogen-containing organic compounds was similar with that of temperature. However, the influence of solid loading rate was insignificant. Moreover, it was also found that the differences of amino acids in the protein components in the two microalgae might affect the nitrogen distribution in products. For example, nitrogen in basic amino acids of Spirulina sp. preferred to go into the aqueous phase comparing with the nitrogen in neutral amino acids of Chlorella sp. In summary, a brief reaction map was proposed to describe the nitrogen pathway during microalgae hydrothermal liquefaction.

关键词： microalgae     hydrothermal liquefaction     biocrude     nitrogen distribution    

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Effect of electrolyte concentration on the tribological performance of MAO coatings on aluminum alloys

Chao Wang, Jun Chen, Jihua He, Jing Jiang, Qinyong Zhang

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 1065-1071 doi: 10.1007/s11705-019-1909-x

摘要： Micro-arc oxidation (MAO) is an efficient approach to improve the hardness, wear resistance, and other properties of aluminum alloys. In order to investigate the effect of the electrolyte concentration on the properties of MAO coatings for LY12 alloy, the voltage variation during the MAO process was recorded. The surface morphologies and phase compositions of the coatings produced with different electrolytes were investigated using scanning electron microscopy and X-ray diffraction, respectively. The roughness and thickness of the coatings were measured using a pocket roughness meter and an eddy-current thickness meter, respectively. The tribological performances of the coatings were investigated against GCr15 bearing steel on a ball-on-disc wear tester in open air. The results showed that with an increase in the Na SiO content, the working voltage of the MAO process decreased, the roughness and thickness of the coatings increased significantly, and the relative content of the -Al O phase decreased. With an increase in the KOH content, the working voltage decreased slightly, the roughness and thickness of the coatings increased slightly, and the α- and -Al O phase contents remained unchanged. The friction coefficient and wear rate of the coatings increased with an increase in the Na SiO and KOH concentrations. A decrease in the porosity and roughness and an increase in the α-Al O content of the coatings reduced their wear mass loss.

关键词： aluminum alloy     micro-arc oxidation     coating     electrolyte concentration     tribological performance    

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SOIL NITROGEN CYCLING AND ENVIRONMENTAL IMPACTS IN THE SUBTROPICAL HILLY REGION OF CHINA: EVIDENCE FROM

《农业科学与工程前沿（英文）》 2022年 第9卷 第3期   页码 407-424 doi: 10.15302/J-FASE-2022448

摘要：

● Soil nitrogen fluxes and influencing factors were reviewed in the subtropical hilly regions.

关键词： nitrogen cycling     soil nitrogen     nitrogen deposition     greenhouse gases emission     non-point source pollution     nitrogen use efficiency    

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PROGRESS ON IMPROVING AGRICULTURAL NITROGEN USE EFFICIENCY: UK-CHINA VIRTUAL JOINT CENTERS ON NITROGEN

《农业科学与工程前沿（英文）》 2022年 第9卷 第3期   页码 475-489 doi: 10.15302/J-FASE-2022459

摘要：

● Virtual joint centers on N agronomy were established between UK and China.

关键词： CINAg     N-CIRCLE     nitrogen use efficiency     reactive nitrogen     sustainable production    

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标题 作者 时间 类型 操作

Modelling the thresholds of nitrogen/phosphorus concentration and hydraulic retention time for bloom

期刊论文

Effects of nitrate concentration on biological hydrogen production by mixed cultures

Bo WANG, Wei WAN, Jianlong WANG,

期刊论文

Nitrogen pollution and source identification of urban ecosystem surface water in Beijing

Yufen REN, Zhiwei XU, Xinyu ZHANG, Xiaoke WANG, Xiaomin SUN, D. J. BALLANTINE, Shengzhong WANG

期刊论文

Mechanism studies on nitrogen removal when treating ammonium-rich leachate by sequencing batch biofilm

XU Zhengyong, YANG Zhaohui, ZENG Guangming, XIAO Yong, DENG Jiuhua

期刊论文

A Novel Electrochemical Reactor for Nitrogen and Phosphorus Recovery from Domestic Wastewater

Shiting Ren, Mengchen Li, Jianyu Sun, Yanhong Bian, Kuichang Zuo, Xiaoyuan Zhang, Peng Liang, Xia Huang

期刊论文

Localized high-concentration electrolytes for lithium metal batteries: progress and prospect

期刊论文

PM concentration declining saves health expenditure in China

期刊论文

Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

期刊论文

SUSTAINABLE NITROGEN MANAGEMENT IN AUSTRALIAN AGROECOSYSTEMS: CHALLENGES AND OPPORTUNITIES

期刊论文

SUSTAINABLE NITROGEN MANAGEMENT FOR VEGETABLE PRODUCTION IN CHINA

期刊论文

EFFECTS OF SUBSTITUTION OF MINERAL NITROGEN WITH ORGANIC AMENDMENTS ON NITROGEN LOSS FROM SLOPING CROPLAND

期刊论文

Nitrogen distribution in the products from the hydrothermal liquefaction of sp. and sp.

期刊论文

Effect of electrolyte concentration on the tribological performance of MAO coatings on aluminum alloys

Chao Wang, Jun Chen, Jihua He, Jing Jiang, Qinyong Zhang

期刊论文

SOIL NITROGEN CYCLING AND ENVIRONMENTAL IMPACTS IN THE SUBTROPICAL HILLY REGION OF CHINA: EVIDENCE FROM

期刊论文

PROGRESS ON IMPROVING AGRICULTURAL NITROGEN USE EFFICIENCY: UK-CHINA VIRTUAL JOINT CENTERS ON NITROGEN

期刊论文